1. Field of the Invention
The present invention relates to an electric contact member that is used for inspection of electric properties of a semiconductor element and repeatedly contacts with an electrode at a tip part of the electric contact member in which the tip part has an edge, and particularly to an electric contact member having excellent durability, which is not deteriorated in conductivity by repeated inspection. Incidentally, the electric contact member of the invention typically includes a contact probe (contact probe pin) formed in a pin shape (needle shape), but also includes, for example, one in a leaf spring shape and one in other shapes. In short, any electric contact member is included, as long as it repeatedly contacts with an electrode at a tip part of the electric contact member in which the tip part has an edge.
2. Description of the Related Art
In electronic parts (that is to say, electronic parts using semiconductor elements) such as integrated circuits (ICs), large-scale integrated circuits (LSIs) and light-emitting diodes (LEDs), electric properties thereof are inspected by bringing electric contact members to contact with electrodes of semiconductor elements. The electric contact members used in such inspection devices (semiconductor inspection devices) are required to have such excellent durability that wear or damage does not occur even by repeated contact with the electrodes as devices under test, as well as good conductivity (low contact resistivity).
Typical examples of the electric contact members (contact terminals) as described above include contact probe pins. The contact resistance of such electric contact members is generally set to 100 mΩ or less, but sometimes deteriorates to several hundred mΩ to several Ω by repeatedly contacting with the devices under test.
As a measure thereof, regular cleaning or replacement of the contact terminals has been conventionally carried out. However, this extremely reduces the reliability and operating rate of an inspection process in some cases, so that other measures have been studied. In particular, solder materials or Sn-plated electrodes have properties that surfaces thereof are easily oxidized, and scraped off because of their softness to easily adhere to the contact terminal side. It is therefore difficult to realize stable contact.
As a method for stabilizing the contact resistance of the electric contact member (hereinafter sometimes represented by “contact probe pin”), there has been proposed a technique of coating the vicinity of a tip part of the contact probe pin (a tip part contacting with an electrode and the vicinity thereof) with a carbon film (for example, JP-A-10-226874, JP-A-2002-318247, JP-A-2003-231203, JP-A-2007-24613). In this technique, it becomes an important requirement to allow an alloy element such as tungsten (W) to be mixed in the carbon film represented by diamond like carbon (DLC) to form a surface film having both low adhesive properties of the carbon film to the device under test (the electrode) and high conductivity due to the presence of the metal (or a carbide thereof) mixed in the carbon film.